Arc extinguishing means



Sept. 29, 1931. a. P. BAKER ARC EXTINGUISHING MEANS Filed May 10, 1929 INVENTOR Ber/0min P56: 4

ATTORNEY Patented Se t; 29, 1931* BENJAMIN LP. BAKER, OF TURTLE CREEK,

PENNSYLVANIA, ASSIGNOR TO WESTING- HOUSE ELECTRIC & MANUFACTURING COMPANY, A CORPORATION OF PENNSYL- VANIA.

ARC EXTINGUISHING MEANS Application filed May 10, 1929. Serial No. 361,865.

My invention relates to circuit interrupters and particularly to arc-extinguishing chambers therefor.

One object of my invention is to provide an arc-extinguishing device in which the arc shall be compelled to traverse a linear path so folded upon itself that the arc shall never traverse a given portion of the path more than once. I

Another object of my invention is to provide an arc-extinguishing device in which the arc shall be compelled, by barriers to traverse a predetermined linear path.

It has been the practice to provide an arcextinguishing chamber with a plurality of closely-spaced metallic plates that separate the are, established at the con'tacts, into a series of short arcs. Arrangements have also beeniprovided which caused the short arcs to rapidly traverse a circular path on the plates. It will be obvious that, if the arc persists for a sufficient length of time, it will again traverse portions of its original path. Such a structure is described by Joseph Slepian in his copending application, Serial No. 181,289, filed April 6, 1927, now Patent 1,7 84,760 dated December 9, 1930 and assigned to Vestinghouse Electric & Manufacturing.

Company, the assignee of the present application. a

In practicing my invention, I provide walls of arc-resisting material between the closely-spaced metallic plates, between which the arc is confined and caused to traverse a spiral path on the surfaces of the plates.

It is another object of my invention to provide an insulating material associated with 5 my invention will best the surface of an arc-extinguishing device to confine the are, moving on the said surface, to a predetermined path.

It is a further object of my invention to provide the surfaces of metallic plates, upon which an arc is moved to be deionized and ex tinguished in the above described manner, with a refractory insulating material ,that shall provide a spiral path for the'arc and thereby prevent it from retracing a path over any portion of the surface already, traversed.

With these principles and objects in mind,

be understood by referring to the following description and drawings, wherein Figure 1 is asectional view of an arc-extinguishing device disclosing a deionizing plate embodying my invention. I

Figs. 2, 3 and 4 are enlarged sectional views taken along the line 11-11 of Fig. 1, showing the difierent forms that embodiments of my invention may assume.

Fig. 5 is a broken central view of the structure illustrated in Fig. 1 disclosing a modified form of the structure embodying my invention.

In the above mentioned. application of Joseph Slepian, a circuit interrupter is described having a deionizing chamber positioned adjacent the contact members. This deionizing chamber includes an enclosing member having a plurality of metal plates in parallel relation with each'other, these plates being spaced apart a very short distance by insulating material. A suitable magnetic field is provided to draw the are into engagement with the plates where it is broken up into a plurality of small arcs in series through the plates. The magnetic field is so arranged that a movement is imparted to the arcs to rotate them between the adjacent surfaces of the plates thereby preventing the excessive heating or volatilization of the plates. When the current of the circuit reaches zero value, during the course of its alternating cycle, the arcs will be extinguished and because of the rapid recovery of dielectric strength of the spaces between the surface, the arc will not restrike when the voltage of the circuit has again increased in value during the alternating cycle.

As set forth in the above application, plates 1 are employed, having an aperture 2 in the center thereof, about which an insulating ring 3, which is preferably of a heat-refractory material, such as asbestos, is positioned. An insulating border 4 is provided around the outer edge of the plate 1, to retain the plates in spaced relation and to confine the arc to the surface of the plates.

In practicing my invention, in order to prevent the arc, in passing over the surface of the plate 1 between the insulating members 7 face of 3 and 4, from traversing the same path by travelling repeatedly about the central opening 2, I have provided the insulatin material 5, shown in Fig. 1, in the shape 0 a spiral, positioned on the plate 1 between insulating members 3 and 4.

As the arc is transferred to the plate 1 and acted upon by the field of the blowsout magnet, it will revolve about the central opening 2 and will be guided between the insulating members 3, 4: and 5 along a spiral path. Such an arrangement prevents any heating and burning of the metal which might occur under some conditions when the arc continues to travel repeatedly over the same ath.

p The structure of Fig. 1 shows a completely closed spiral path. In the event it is found desirable to permit the arc to retravel some portion of the path more than once per interruption, the end of the innermost spiral may be left open as shown in Fig. 5, thus permitting the arc to repeatedly travel a spiral path. It will also above. Ways of arranging magnetic fields to cause an arc to traverse zig-zag or other multiple fold paths will be readily apparent to those skilled in the art. Broadly, my invention comprehends the extinction of an are by compelling it to travel only upon a predetermined linear path by reason of the fact that it is confined between insulating walls; and the folding of the linear path which an arc is compelled to traverse.

In Fig. 2, the insulating members 5 are positioned equidistant from each other and are of such widths as to bridge the distance between the adjoining plates 1, while such a f structure prevents the are from passing transversely fromone section into another, it may be disadvantageous in certain applications, because it traps the accumulated gases and thereby impedes the rapid movement of the arc.

In Fig. 3, the insulating material 5 is an insulating cement that is placed on the surone of the plates and is spaced away from the adjacent plate. Such a construc tion permits the gases to pass freely between the plates and, at the same time, marks out the path for the are over the surface of the plates as the arc continues to travel in a spiral path.

In Fig. 4, a sectional view is shown similar to that of Figs. 2 and 3, with the exception that the insulating member 5 is mechanically supported in a spiral slot 6 in each alternate plate, so that the plates may be removed without any danger of the insulating material being loosened or removed fromits predetermined position. It will be recognized that it is possible to provide every plate instead of every alternate plate with a spiral groove;

be evident that the guiding wall of insulation may be made of configuration other than the spiral described and to omit the solid insulating material also if desired. Thus a deionizing structure comprising a plurality of metal spirals positioned side by side is within the purview of my invention.

It will thus be seen that I have provided an arrangement comprising deionizin plates in which the arc is confined to a pre etermined path and is prevented from traversing an portion of the path over which it had previously travelled. Other novel features of my invention are. the method of mechanicall attaching the insulating material to the p ates and also the provision of short gaps that permit the gas to find egress from one space to another and thus to be carried away.

While I have described several embodiments of my invention, it is to be understood that many additions, subtractions, chan and substitutions may be made without eparting from the spirit and sco of my invention. I desire, therefore, t at the appended claims shall be limited only by the prior art.

I claim as my invention:

1. The combination with an arc-extinguishing chamber for a circuit interrupter, of a plurality of spaced metallic plates associated therewith, a magnetic field associated with the plates to cause an are between said plates to move repeatedly thereon, and insulati guide members on the surface of the plates to cause the arc to move over different portions of the surfaces thereo 2. The combination with an arc-extinguishing chamber, of a lurality of spaced metallic plates associated t erewith, means for causi an are established between the lates to mpeatedly move thereon,.and insu ating means or guidin the said movement over a predetermine linear path upon the surface of the said plates. v

3. The combination with an arc-extinguishing chamber, of a plurality of spaced conductors associated therewith, means for causing the are established across the conductors to repeatedly move thereon, and means for com-' pelling said are to tra erse a predetermined linear path. I

4. The combination with an arc-extinguishing chamber, of a plurality of spaced conductors associated therewith, means for causing the are established across'the conductors to revolve on the surface thereof and means constituting a folded non-recurrent path for said arc.

5. The combination with an arc-extingushing chamber for a plurality of spaced metallic plates associated therewith, means for causin series related associated with said surfaces the arcs to traverse a tortuous Ill circuit interrupter, of a ing chamber, of a plurality of spaced conductors associated therewith, means fortransferring the terminals of an arc to the surfaces of said conductors, means for movin the are 5 on said surfaces and means for compe ling the arc to traverse a tortuous path thereon.

7 The combination with an arc-extinguishing chamber, of a plurality of spaced metallic plates associated therewith, means for trans- 10 ferring an arc to the plates to establish a plurality of series related short arcs therebetween, and means associated with a portion of the plates for providing confined paths for the arcs over the surfaces of the plates.

8. The combination with an arc-extinguishing chamber for a circuit interrupter, of a plurality of spaced metallic plates associated therewith, meansfor establishing an are between the plates, and means associated with at least one of the plates for providing a nonrecurrent path of revolution for the are over the surface of the plates.

9. The combination with an arc-extinguishing chamber for a circuit interrupter, of a 2 plurality of spaced metallic plates and a magnetic field to cause the are between said plates to move thereon, and guide members on the plates so arranged that the arcs are caused to move only once over certain portions'of "the 80 plate surface and repeatedly over other portions of its surface.

10. The combination with an arc-extinguishing chamber, of a plurality of spaced conductors associated therewith for dividing 85 the are into a plurality of short arcs, means for causing the arcs established across the conductors to move thereon, and means for compelling said arcs to repeatedly traverse a predetermined non-rccurrent linear path.

40 11. The combination with an arc-extinguishing chamber, of a plurality of spaced conductors associated therewith, means for transferring an arc to the surfaces between the conductors, and means for compelling the terminals of the short arcs thus established to traverse a tortuous non-recurrent path.

. 12. The combination with an arc-extinguishing chamber, of a plurality of spaced conductors associated therewith for dividing the arc into a plurality of short arcs, and means for compelling said arcs to traverse a predetermined linear path without substantially lengthening the arc.

In testimony whereof, I have hereunto subscribed my name this 7th day of May, 1929.

BENJAMIN P. BAKER. 

